Polymorphic and Morphological Transformation during the Transition from a Propagating Band to Static Bands in the Nickel Hydroxide/Ammonia Liesegang System

2011 ◽  
Vol 312-315 ◽  
pp. 800-805 ◽  
Author(s):  
Mazen Al-Ghoul ◽  
Manal Ammar
Keyword(s):  
Experimental Study ◽  
Nickel Hydroxide ◽  
Pulse Propagation ◽  
Ostwald Ripening ◽  
Reaction Diffusion ◽  
Polymorphic Transition ◽  
The Other ◽  
Precipitation Reaction ◽  
Morphological Transformation ◽  
Ostwald Ripening Mechanism

We present an experimental study of the Ni+2/Ni(OH)2/NH3 reaction-diffusion system in a gel (agar). The system, which consists of a gel containing an inner electrolyte Ni+2 and a diffusing outer electrolyte (NH3/OH-), exhibits pulse propagation due to the concomitant precipitation reaction between Ni+2 and hydroxide ions and re-dissolution due to ammonia. During the propagation of the pulse, a transition to Liesegang banding is shown to take place. The bands are characterized by IR and XRD and are shown to consist of the polymorph -Ni(OH)2 whereas the pulse contains the other polymorph -Ni(OH)2. SEM measurements also reveal a morphological change accompanying the polymorphic transition between the pulse and the bands and uncovering an Ostwald ripening mechanism.

Effectiveness of Virtual Resilience Training on Assertiveness in Student Girls Aged 9–10 Years: A 1-Month Follow-Up

2021 ◽  
pp. 105984052110135
Author(s):  
Shima Gadari ◽  
Jamile Farokhzadian ◽  
Parvin Mangolian Shahrbabaki
Keyword(s):  
Experimental Study ◽  
Internal Stress ◽  
Intervention Group ◽  
The Other ◽  
Hormonal Changes ◽  
Emotional Instability ◽  
Other Hand ◽  
Significant Difference ◽  
Resilience Training

Girls between the ages of 9 and 10 begin to experience physical, physiological, and hormonal changes that may lead to internal stress. At this age, children are struggling for autonomy; on the other hand, they may experience emotional instability, and for these reasons, they may be vulnerable in many ways. This experimental study aimed to investigate the effect of resilience training on assertiveness in student girls aged 9–10. Data were collected before, immediately after, and 1 month after the intervention in the control ( n = 40) and intervention ( n = 37) groups. There was a significant difference between the assertiveness of the intervention immediately (26.80 ± 3.73) and 1 month after the intervention (27.05 ± 3.73), and assertiveness significantly increased in the intervention group ( p = .0001). Resilience training leads to improvements in assertiveness in student girls aged 9–10.

Illite-smectites and the influence of burial diagenesis on the geochemical cycling of nitrogen

Clay Minerals ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 539-546 ◽  
Author(s):  
P. A. Schroeder ◽  
A. A. McLain
Keyword(s):  
Reaction Mechanisms ◽  
Ostwald Ripening ◽  
Precipitation Reaction ◽  
Oil Well ◽  
Burial Diagenesis ◽  
Fixed Nitrogen ◽  
Geochemical Cycling ◽  
Oil Generation ◽  
Fraction Increase ◽  
Changing Rate

AbstractFixed nitrogen in illite-smectites (I-S) has been measured for Miocene shales from a Gulf of Mexico oil well. Fixed N values for the <0.2 µm fraction increase with depth from 150 ppm (1000 m) to a maximum of 360 ppm (3841 m). This increase is coincident with illitization from 41% I in I-S to 75% I in I-S. Below 3841 m, fixed N values decrease to 190 ppm (4116 m) while I-S is maintained with a slight increase from 77 to 82%. The changes in fixed N with increasing illitization are consistent with the notion that illitization proceeds via both transformation and dissolution/ precipitation reaction mechanisms. The trend of decreasing fixed N in illitic I-S is compatible with surface-controlled crystal growth and Ostwald ripening mechanisms for illitization. The trend may also be linked to the timing of maximum NH] release from kerogen maturation during oil generation. The changing rate of NH+4 liberation from organic matter and multiple illitization reaction mechanisms can result in complex N geochemical cycling pathways throughout early diagenesis to metamorphism.

Study of wave attenuation in concrete

1993 ◽  
Vol 8 (9) ◽  
pp. 2344-2353 ◽  
Author(s):  
J-M. Berthelot ◽  
Souda M. Ben ◽  
J.L. Robert
Keyword(s):  
Experimental Study ◽  
Plane Wave ◽  
Wave Attenuation ◽  
Plane Waves ◽  
Propagation Distance ◽  
Experimental Results ◽  
The Other ◽  
Wave Frequency ◽  
Concrete Composition ◽  
Analytical Expression

The experimental study of wave attenuation in concrete has been achieved in the case of the propagation of plane waves in concrete rods. Different mortars and concretes have been investigated. A transmitter transducer coupled to one of the ends of the concrete rod generates the propagation of a plane wave in the rod. The receiver transducer, similar to the previous one, is coupled to the other end of the rod. The experimental results lead to an analytical expression for wave attenuation as function of the concrete composition, the propagation distance, and the wave frequency.

Experimental Study on Racetrack-Shaped Holes Impingement Cooling With Bump Type Roughening Element

2012 ◽  
Author(s):  
Chiyuki Nakamata ◽  
Yoji Okita ◽  
Takashi Yamane ◽  
Yoshitaka Fukuyama ◽  
Toyoaki Yoshida
Keyword(s):  
Experimental Study ◽  
Flow Condition ◽  
Reynolds Numbers ◽  
Main Flow ◽  
The Other ◽  
Relative Location ◽  
Target Plate ◽  
Cooling Effectiveness ◽  
Impingement Cooling ◽  
Cooling Air

Cooling effectiveness of an impingement cooling with array of racetrack-shaped impingement holes is investigated. Two types of specimens are investigated. One is a plain target plate and the other is a plate roughened with bump type elements. Sensitivity of relative location of bump to impingement hole on the cooling effectiveness is also investigated. Experiments are conducted under three different mainflow Reynolds numbers ranging from 2.6×105 to 4.7×105, with four different cooling air Reynolds numbers for each main flow condition. The cooling air Reynolds numbers are in the range from 1.2×103 to 1.3×104.

Tribological Study of Polymer Composite Forming Using Model Experiments and Real Composites

2014 ◽  
Vol 611-612 ◽  
pp. 300-305 ◽  
Author(s):  
Olga Smerdova ◽  
Michael P.F. Sutcliffe
Keyword(s):  
Experimental Study ◽  
Polymer Composites ◽  
Viscous Liquid ◽  
Polymer Composite ◽  
Contact Area ◽  
Essential Feature ◽  
The Other ◽  
Carbon Fabric ◽  
Simultaneous Application ◽  
Composite Forming

This experimental study is focused on identification of tribological mechanisms acting during forming of polymer composites. The range of relevant processes includes fibre placement, tape lay-up, moulding, draping, and RTM. Two types of tribological experiments, relying both on simultaneous application of compression and shear loadings, are carried out. Firstly, model macromechanical tests are undertaken on plastic rods of millimetric diameter immersed in a viscous liquid, representing composite fibres and matrix, respectively. By careful simulation of forming conditions, this experiment helps to identify the friction phenomena occurring in real composites. On the other hand, the micromechanics of forming processes is studied through a microscopic experiment on real carbon fabric. This material is clamped between two glass plates and pulled in opposing directions in the plane of the fabric. It is hypothesized that the evolution of contact area due to shearing that can be measured in this experiment is an essential feature of the tribology of forming processes, a topic which hitherto has not been investigated.

The Mindfulness-Based Stress Reduction Program (MBSR) Reduces Stress-Related Psychological Distress in Healthcare Professionals

2010 ◽  
Vol 13 (2) ◽  
pp. 897-905 ◽  
Author(s):  
Andrés Martín-Asuero ◽  
Gloria García-Banda
Keyword(s):  
Experimental Study ◽  
Psychological Distress ◽  
Stress Reduction ◽  
Health Professionals ◽  
Healthcare Professionals ◽  
Training Programs ◽  
The Other ◽  
Reduction Program ◽  
Mindfulness Based Stress Reduction

This semi-experimental study examines how Mindfulness facilitates a distress reduction in a group of health professionals. The sample comprises 29 professionals seeking stress reduction who undertook an 8 weeks psico-educative intervention, involving 28 hours of class, based on a program called Mindfulness-based Stress Reduction or MBSR. Results show a 35% reduction of distress, from percentile 75 to 45, combined with a 30% reduction in rumination and a 20% decrease in negative affect. These benefits lasted during the 3 months of the follow up period. The correlation analysis indicates that the decrease in distress is significantly related to the other two variables. These results confirm the effectiveness of MBSR to decrease distress and its applicability in training programs for health professionals.

scholarly journals Modified method for bronchial suture by Ramirez Gama compared to separate stitches suture: experimental study

2014 ◽  
Vol 41 (3) ◽  
pp. 188-192
Author(s):  
Vitor Mayer de Moura ◽  
Erinaldo Rocha Paes Lamdim ◽  
Felipe Souza Ferraz ◽  
Rodrigo Carvalho Turatti ◽  
Carolina de Barros Jaqueta ◽  
...  
Keyword(s):  
Experimental Study ◽  
The Other ◽  
Compressed Air ◽  
Air Leak ◽  
Bronchial Stump ◽  
Modified Method ◽  
Tracheal Pressure ◽  
Air Ventilation ◽  
Manual Suture ◽  
Isolated Trachea

OBJECTIVE: To experimentally compare two classic techniques described for manual suture of the bronchial stump. METHODS: We used organs of pigs, with isolated trachea and lungs, preserved by refrigeration. We dissected 30 bronchi, which were divided into three groups of ten bronchi each, of 3mm, 5mm, and 7mm, respectively. In each, we performed the suture with simple, separated, extramucosal stitches in five other bronchi, and the technique proposed by Ramirez and modified by Santos et al in the other five. Once the sutures were finished, the anastomoses were tested using compressed air ventilation, applying an endotracheal pressure of 20mmHg. RESULTS: the Ramirez Gama suture was more effective in the bronchi of 3, 5 and 7 mm, and there was no air leak even after subjecting them to a tracheal pressure of 20mmHg. The simple interrupted sutures were less effective, with extravasation in six of the 15 tested bronchi, especially in the angles of the sutures. These figures were not significant (p = 0.08). CONCLUSION: manual sutures of the bronchial stumps were more effective when the modified Ramirez Gama suture was used in the caliber bronchi arms when tested with increased endotracheal pressure.

Divergent theories, converging evidence: The constructional semantics of competing future constructions

2018 ◽  
Vol 6 (1) ◽  
pp. 91-114
Author(s):  
Stefan Hartmann
Keyword(s):  
Experimental Study ◽  
The Other ◽  
Temporal Distance ◽  
Corpus Study ◽  
Distant Future ◽  
Other Hand ◽  
Future Events ◽  
The One ◽  
Near Future ◽  
Lines Of Evidence

Abstract This paper investigates the alternation between two competing German future constructions, the werden + Infinitive construction and the futurate present, from a usage-based perspective. Two lines of evidence are combined: On the one hand, a pilot corpus study indicates that werden + Infinitive is more likely to be used for referring to distant-future events than to near-future events. However, syntactic factors seem to be at least as decisive as semantic ones for speakers’ choice between the two constructions. On the other hand, an experimental study taps into language users’ interpretation of sentences framed in one of the two constructions. It can be shown that the grammatical framing does not significantly affect participants’ estimates of the temporal distance of the events to which the stimuli sentences refer. This suggests that the meaning differences between the two constructions be more nuanced, e.g. pertaining to discourse-pragmatic functions.

scholarly journals Development of cyclosporine-loaded nanoemulsion for topical treatment of psoriasis

2019 ◽  
Vol 10 (SPL1) ◽  
Author(s):  
Siti Hajar Musa ◽  
Norazlinaliza Salim ◽  
Norashikin Shamsudin ◽  
Mahiran Basri ◽  
Hamid Reza Fard Masoumi
Keyword(s):  
Topical Treatment ◽  
Oral Delivery ◽  
Ostwald Ripening ◽  
Normal Skin ◽  
Severe Case ◽  
Transepidermal Water Loss ◽  
Water Soluble ◽  
Colloidal System ◽  
Thaw Cycle ◽  
Ostwald Ripening Mechanism

Psoriasis is an autoimmune disease in which the symptoms are obviously appeared on the patient's body with thick, red/ salmon colour and dry patches. Clinically, topical treatment has been the first-line treatment for psoriasis, whether or not the systemic and phototherapy is required. Currently, cyclosporine is one of the standard oral medications used for moderate to a severe case of psoriasis. However, through oral delivery, it cannot be used for a long period and causes bad effects. Thus, a new delivery system of cyclosporine is in need to be developed to overcome its toxic effects by skipping the first pass body metabolism. A nanoemulsion colloidal system, as the main carrier for big, non-water-soluble cyclosporine, is believed could help in the delivery of activities through the stratum corneum of the skin layer. Nanoemulsion system, which mainly consists of oil phase (a mixture of virgin coconut oil, nutmeg oil, and cyclosporine), aqueous phase, and surfactant, was successfully being developed by using Mixture Experimental Design optimization tool with droplet size range between 110-160 nm. Stability studies were carried out with respect to; pH, storage at different temperatures, coalescence and Ostwald ripening mechanism, free-thaw cycle, and FTIR analysis. From the obtained results, this newly-developed nanoemulsion containing cyclosporine was proven to be stable and successfully maintained its physicochemical characteristics even after 3 months of storage at 4°C and 25°C temperature. Ostwald ripening mechanism contributed to the instability of the system at 45°C of storage. Introduction of standard cyclosporine, blank nanoemulsion, and nanoemulsion containing cyclosporine to the HaCaT cells in the treatment of MTT assay study has confirmed the safety of the nanoemulsion. Permeation study of the newly-developed nanoemulsion containing cyclosporine showed it was best fitted the Korsmeyer-Peppas kinetic model. In addition, the transepidermal water loss and hydration studies proved the efficacy of cyclosporine-loaded nanoemulsion in increasing the water storage of the volunteers’ normal skin after 3h of application.  

scholarly journals The Stroop Task Influences Product Evaluations

2021 ◽  
Vol 12 ◽  
Author(s):  
Tom G. E. Damen
Keyword(s):  
Experimental Study ◽  
Stroop Task ◽  
Cognitive Conflict ◽  
Bottled Water ◽  
The Other ◽  
Product Evaluations ◽  
Study Participants ◽  
Negative Signal

Cognitive conflict is considered to represent a psychologically negative signal. Indeed, a recent publication showed that cognitive conflict emerging from the Stroop task influences evaluations for neutral shapes that had become associated with conflict and non-conflict, respectively. Building on these findings, the present research investigates the degree to which Stroop conflict influences evaluations of actual products. In an experimental study, participants performed a Stroop task in which they responded to conflict trials (e.g., the word red presented in a blue font) as well as non-conflict trials (e.g., the word red presented in a red font). Participants were also presented with two pictures featuring bottled water brands: One brand was consistently presented after non-conflict trials; the other brand was consistently presented after conflict trials. When participants evaluated the products, the results showed they rated the product associated with Stroop conflict less favorably than the product associated with non-conflict; however, this effect only emerged when participants were thirsty. When participants were not thirsty, no differences emerged. The present findings add to the literature on cognitive conflict and negativity, suggesting that Stroop conflict can influence product evaluations when those products are goal relevant.

Sign in / Sign up

Export Citation Format

Share Document